1. Field of the Invention
The present invention relates to a method for forming an headrest for use on an automotive seat by means of a foaming process wherein a liquid base foaming material is injected into within a trim cover assembly of donut-like or tubular ringed shape and cured therein to form a corresponding shape of headrest, and also to the resulting headrest formed by that method.
2. Description of Prior Art
Among various sorts of headrests, there has been known a donut-like or generally tubular ringed shape of headrest having a through-hole formed centrally of and through its body. Typically, forming this headrest is based on a foaming process, using a foaming die device. At an initial step, several separate covering material sections are sewn together to provide a three-dimensional donut-like or generally tubular ringed shape of covering member having an through-hole centrally thereof. Along this covering member, an annular opening portion is defined, which allows entry of a headrest frame with headrest stay portions into within the covering member. Next, the headrest frame is placed in the thus-formed covering member through such annular opening portion, with the headrest stay portions projecting outwardly through another corresponding holes formed in the covering member. Then, as for example disclosed from the Japanese Laid-Open Publication No. 1-153183, a sealing member is secured via plural snapping points to the annular opening portion to close the same, after which, such sealed covering material is placed in a foaming die and subjected to a foaming process. During the foaming operation, the sealing member serves to prevent leakage of the liquid base foaming material from the annular opening portion of covering member.
However, in this sort of conventional method, the material of covering member used is rather soft and unsteady, with the result that a portion of the covering material secured to the foregoing sealing material creates creases or wrinkles therein, which makes incomplete the sealing of the covering member. As a consequence thereof, it has been found defective that, during the foaming process, the liquid base foaming material filled in the sealed covering member is easily leaked from the creased or wrinkled portion of covering material around the sealing member, and an objectionable staining points of cured foaming material appears on the surface of resultant headrest, impairing its outer aesthetic appearance.